Perineural Invasion is a Major Prognostic and Predictive Factor of Response to Adjuvant Chemotherapy in Stage I-II Colon Cancer.

BACKGROUND: Perineural invasion (PNI) in colon cancer (CC) has been associated with poorer prognosis even in stage II disease (T3-4 N0 M0). The aim of this study is to analyze prognostic histopathologic factors in stage II colon cancer in patients treated with curative surgery as established in National Comprehensive Cancer Network guidelines. METHODS: From a prospective database of CC cases, 507 patients with stage I-II disease who had undergone curative resection from January 2000 and December 2012 were identified. Of these patients, 17 % received 5-flurouracil-based adjuvant chemotherapy. Together with demographic and anatomic variables, we also studied perineural and lymphovascular invasion, degree of differentiation, and their correlation with disease-free survival. RESULTS: Perineural invasion was identified in 57 patients (11.2 %) and lymphovascular invasion (LVI) in 82 (16.2 %) of the 507 patients. Perineural invasion was associated with LVI, the depth of invasion of the wall of the colon, and location of the tumor. Overall and disease-free survival of the complete series at 5 and 10 years was 89.5, 85.2, 83.2 and 81.6 %, respectively. In the PNI positive patients, disease-free survival at 5 years was significantly lower than in those without PNI (73.5 vs 88.6 %; p = 0.02). Multivariate analysis showed the presence of PNI to be a significant independent prognostic factor for disease-free survival (p = 0.025). Adjuvant chemotherapy reversed the impact of PNI on 5- to 10-year disease-free survival. CONCLUSIONS: PNI a major prognostic and predictive factor in stage II colon cancer, and our results support the use of adjuvant chemotherapy in patients with PNI.

Impact of perineural and lymphovascular invasion on oncological outcomes in rectal cancer treated with neoadjuvant chemoradiotherapy and surgery.

BACKGROUND: The prognostic significance of perineural and/or lymphovascular invasion (PLVI) and its relationship with tumor regression grade (TRG) in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (CRT) and surgery. METHODS: A total of 324 patients with LARC were treated with CRT and operated on between January 1992 and June 2007. Tumors were graded using a quantitative 5-grade TRG classification and the presence of PLVI was histologically studied. RESULTS: At a median follow-up of 79.0 months (range 3-250 months), a total of 80 patients (24.7%) relapsed. The observed 5- and 10-year overall survival (OS) was 83.2 and 74.9 %, respectively. The 5- and 10-year disease-free survival (DFS) was 75.1 and 71.4%, respectively. A significant correlation was found between the TRG and survival (log rank, p < 0.001). The 10-year OS was 32.7% for grade 1, 63.8% for grade 2, 75.0% for grade 3, 90.4% for grade 3+, and 96.0%,for grade 4. The 10-year DFS was 31.8% for grade 1, 58.6% for grade 2, 70.4% for grade 3, 88.4% for grade 3+, and 97.1% for grade 4. In patients with PLVI, the TRG had no impact on survival. When excluding patients with PLVI, the TRG was an independent prognostic factor for OS and DFS. CONCLUSIONS: The presence of PLVI is a more powerful prognostic factor than TRG in LARC patients treated with neoadjuvant CRT followed by surgery. PLVI denotes an aggressive phenotype, suggesting that these patients may benefit from adjuvant systemic therapy.

Preliminary outcome of a treatment strategy based on perioperative chemotherapy and surgery in patients with locally advanced colon cancer.

AIM: Preoperative chemotherapy followed by radical surgery is an attractive treatment for locally advanced colon cancer (LACC) given the promising results of this approach in other locally advanced tumours. The study evaluates the outcome and treatment-related complications of perioperative oxaliplatin- and capecitabine-based chemotherapy and surgery for clinical Stage III colon cancer. METHOD: Twenty-two consecutive patients with a CT-staged LACC were included. All were staged at baseline and before surgery. Surgery-related complications and oncological outcome were determined. RESULTS: Toxicity was manageable, with 19/22 patients completing the planned chemotherapy protocol. The median time from initial diagnosis to surgery was 65.5 days. The median time from the end of chemotherapy to surgery was 22 days. After neoadjuvant treatment, tumour reduction of 69.5% was observed by CT scan and a 59.9% decrease of SUVmax (standard uptake value) was achieved on positron emission tomography/CT. No progressive disease was reported during preoperative chemotherapy and surgery was performed in all 22 patients. Four patients developed postoperative complications. After a median postoperative follow-up of 14.4 months, the actuarial overall and disease-free survival rates were 100 and 90%. CONCLUSION: Neoadjuvant chemotherapy followed by surgery and chemotherapy for LACC is safe without apparent increase of early and medium-term complications.